Casualties of anything from house blazes to road accidents can now receive life-saving treatment even if the fire brigade arrives before the ambulance service.
Firefighters from Hillingdon's Green Watch were the first to model new Immediate Emergency Care (IEC) packs, which will be standard equipment for the borough's four fire stations.
The improved first aid kits include defibrillators, as well as state-of-theart instruments for opening people's airways, preventing spinal injuries and better dressings for wounds.
The introduction of the kit, which includes training in how to use the packs correctly, is designed to ensure casualties who need immediate attention get the help required until a paramedic can take over.
The London Ambulance Service has supported the plan and played a part in developing the new packs as well as providing first aid training.
Hillingdon Borough Commander Gerard Hollingworth said: "At incidents where circumstances prevent early access for paramedics, such as blocked access or unsafe structures, and where we are the first emergency service on the scene, our IEC equipment will significantly increase the chances of survival for casualties and help us provide the very best first aid care for both the public and our own firefighters at incidents."
Duty station officer Chris Miles, from the London Ambulance Service, added: "When a patient is in a life-threatening condition, such as cardiac arrest, every second counts in getting the best possible care to them.
"Effective cardiopulmonary resuscitation (CPR) prior to our arrival can double the patient's chance of survival, while the use of a defibrillator can increase their chances of survival by more than a third.
"This is just one example of the ways that the service has worked to increase the capital's cardiac arrest survival rate in the last few years.
"If the LFB arrive at an incident prior to us, their IEC equipment and training means they can start potentially life-saving treatment of casualties which can only be a good thing for the public across the Borough of Hillingdon."